From patchwork Fri Jun 26 06:29:48 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Herbert Xu X-Patchwork-Id: 11626585 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 406DA161F for ; Fri, 26 Jun 2020 06:30:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3024120724 for ; Fri, 26 Jun 2020 06:30:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728418AbgFZGad (ORCPT ); Fri, 26 Jun 2020 02:30:33 -0400 Received: from helcar.hmeau.com ([216.24.177.18]:51990 "EHLO fornost.hmeau.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727876AbgFZGac (ORCPT ); Fri, 26 Jun 2020 02:30:32 -0400 Received: from gwarestrin.arnor.me.apana.org.au ([192.168.0.7]) by fornost.hmeau.com with smtp (Exim 4.92 #5 (Debian)) id 1johrw-0004mR-T7; Fri, 26 Jun 2020 16:29:50 +1000 Received: by gwarestrin.arnor.me.apana.org.au (sSMTP sendmail emulation); Fri, 26 Jun 2020 16:29:48 +1000 Date: Fri, 26 Jun 2020 16:29:48 +1000 From: Herbert Xu To: Eric Biggers Cc: Naresh Kamboju , Luis Chamberlain , LTP List , open list , linux-security-module@vger.kernel.org, keyrings@vger.kernel.org, lkft-triage@lists.linaro.org, linux-crypto@vger.kernel.org, Jan Stancek , chrubis , "Serge E. Hallyn" , James Morris , Jarkko Sakkinen , David Howells , "David S. Miller" , Sachin Sant , Linux Next Mailing List , linuxppc-dev@lists.ozlabs.org Subject: [PATCH] crypto: af_alg - Fix regression on empty requests Message-ID: <20200626062948.GA25285@gondor.apana.org.au> References: <20200622224920.GA4332@42.do-not-panic.com> <20200623064056.GA8121@gondor.apana.org.au> <20200623170217.GB150582@gmail.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200623170217.GB150582@gmail.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: On Tue, Jun 23, 2020 at 10:02:17AM -0700, Eric Biggers wrote: > > The source code for the two failing AF_ALG tests is here: > > https://github.com/linux-test-project/ltp/blob/master/testcases/kernel/crypto/af_alg02.c > https://github.com/linux-test-project/ltp/blob/master/testcases/kernel/crypto/af_alg05.c > > They use read() and write(), not send() and recv(). > > af_alg02 uses read() to read from a "salsa20" request socket without writing > anything to it. It is expected that this returns 0, i.e. that behaves like > encrypting an empty message. > > af_alg05 uses write() to write 15 bytes to a "cbc(aes-generic)" request socket, > then read() to read 15 bytes. It is expected that this fails with EINVAL, since > the length is not aligned to the AES block size (16 bytes). This patch should fix the regression: ---8<--- Some user-space programs rely on crypto requests that have no control metadata. This broke when a check was added to require the presence of control metadata with the ctx->init flag. This patch fixes the regression by removing the ctx->init flag. This means that we do not distinguish the case of no metadata as opposed to an empty request. IOW it is always assumed that if you call recv(2) before sending metadata that you are working with an empty request. Reported-by: Sachin Sant Reported-by: Naresh Kamboju Fixes: f3c802a1f300 ("crypto: algif_aead - Only wake up when...") Signed-off-by: Herbert Xu diff --git a/crypto/af_alg.c b/crypto/af_alg.c index 9fcb91ea10c4..2d391117c020 100644 --- a/crypto/af_alg.c +++ b/crypto/af_alg.c @@ -635,7 +635,6 @@ void af_alg_pull_tsgl(struct sock *sk, size_t used, struct scatterlist *dst, if (!ctx->used) ctx->merge = 0; - ctx->init = ctx->more; } EXPORT_SYMBOL_GPL(af_alg_pull_tsgl); @@ -757,8 +756,7 @@ int af_alg_wait_for_data(struct sock *sk, unsigned flags, unsigned min) break; timeout = MAX_SCHEDULE_TIMEOUT; if (sk_wait_event(sk, &timeout, - ctx->init && (!ctx->more || - (min && ctx->used >= min)), + !ctx->more || (min && ctx->used >= min), &wait)) { err = 0; break; @@ -847,7 +845,7 @@ int af_alg_sendmsg(struct socket *sock, struct msghdr *msg, size_t size, } lock_sock(sk); - if (ctx->init && (init || !ctx->more)) { + if (!ctx->more && ctx->used) { err = -EINVAL; goto unlock; } @@ -858,7 +856,6 @@ int af_alg_sendmsg(struct socket *sock, struct msghdr *msg, size_t size, memcpy(ctx->iv, con.iv->iv, ivsize); ctx->aead_assoclen = con.aead_assoclen; - ctx->init = true; } while (size) { diff --git a/crypto/algif_aead.c b/crypto/algif_aead.c index d48d2156e621..749fe42315be 100644 --- a/crypto/algif_aead.c +++ b/crypto/algif_aead.c @@ -106,7 +106,7 @@ static int _aead_recvmsg(struct socket *sock, struct msghdr *msg, size_t usedpages = 0; /* [in] RX bufs to be used from user */ size_t processed = 0; /* [in] TX bufs to be consumed */ - if (!ctx->init || ctx->more) { + if (ctx->more) { err = af_alg_wait_for_data(sk, flags, 0); if (err) return err; diff --git a/crypto/algif_skcipher.c b/crypto/algif_skcipher.c index a51ba22fef58..5b6fa5e8c00d 100644 --- a/crypto/algif_skcipher.c +++ b/crypto/algif_skcipher.c @@ -61,7 +61,7 @@ static int _skcipher_recvmsg(struct socket *sock, struct msghdr *msg, int err = 0; size_t len = 0; - if (!ctx->init || (ctx->more && ctx->used < bs)) { + if (ctx->more && ctx->used < bs) { err = af_alg_wait_for_data(sk, flags, bs); if (err) return err; diff --git a/include/crypto/if_alg.h b/include/crypto/if_alg.h index ee6412314f8f..08c087cc89d6 100644 --- a/include/crypto/if_alg.h +++ b/include/crypto/if_alg.h @@ -135,7 +135,6 @@ struct af_alg_async_req { * SG? * @enc: Cryptographic operation to be performed when * recvmsg is invoked. - * @init: True if metadata has been sent. * @len: Length of memory allocated for this data structure. */ struct af_alg_ctx { @@ -152,7 +151,6 @@ struct af_alg_ctx { bool more; bool merge; bool enc; - bool init; unsigned int len; };